Wheel diameter must be as originally fitted unless permitted in (the Spec Sheets). Tires must be mounted following the manufacturers specification for wheel width. Bodywork may not be modified beyond period specifications to accommodate approved tires.

Since tires are a consumable item, SVRA requires tires that are currently available and are of a reasonable age. There is no doubt that modern tire compounds and construction are vastly improved from what was available to competitors when our cars were originally raced. The intent of these rules is to specify tires that are a reasonable compromise between the tires raced with during the period and what is currently available. Availability in sufficient sizes to maintain equitable tire performance within the Group and Class structure is of primary importance. We are looking for an appropriate level of dry grip for all the cars in a group, to avoid overloading suspension components. Tires are evaluated by looking at their aspect ratio, tread pattern, carcass design and wear rating. Some tire sizes/brands are acceptable based on true tire diameter and crosssection regardless of the listed aspect ratio. Some tires listed have been discontinued. These “Legacy” tires remain on the list as long as the age of the existing stock /sizes remain safe for racing use.

Group 1 - Molded Treaded Tires Minimum aspect ratio of 60, except as listed on the right, tread depth— no less than 2/32” remaining, at all times, over 75% of the tire.

Note: Bodywork may NOT be modified beyond period specifications to accommodate listed Any Treaded, DOT approved Tires with a UTQG of 100 or greater with appropriate tires.

Speed Rating and a minimum Aspect Ratio of 60

Wheels may be of an alternate material but must be of period design. They must be the correct diameter and width as specified within the Make and Model Regulations.

For Toyo RA1’s and Nitto NT01’s, please see page 6 of this document

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Group 2 - Molded Treaded Tires As listed on right or in the latest Monoposto Racing Rules and Regulations. Monoposto prepared FF’s will use Monoposto rules and regulations, please find the rules at monoposto.com

Note: Bodywork may NOT be modified beyond period specifications to accommodate listed tires. Note: Please refer to the “Group 3 Description and Class List” for Porsche 356 tire limitations and requirements.

Any Treaded, DOT approved Tires with a UTQG of 100 or greater with appropriate Speed Rating and a minimum Aspect Ratio of 60 Wheels may be of an alternate material but must be of period design. They must be the correct diameter and width as specified within the Make and Model Regulations. Tires may not extend beyond the fender opening at the highest point of the tire.

For Toyo RA1’s and Nitto NT01’s, please see page 6 of this document

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Group 4 - Molded Treaded Tires

Approved Tires:

Tires may not extend beyond the fender opening at the highest point of the tire.

Tires may not extend beyond the fender opening at the highest point of the tire. Specifically Prohibited for Group 6: Any tire not listed in the Approved Tire list Wheels may be of an alternate material but must be of period design. They must be the correct diameter and width as specified within the Make and Model Regulations.

Racing slicks and treaded racing tires. While exact size and aspect ratio are not specified, entrants must ensure that tire choice is appropriate for the car during the eligibility period.

Group 8 - Molded Treaded Tires

Approved tires:

Minimum aspect ratio of 45, except certain car Make and Models, which have specific tire requirements listed in their Supplemental Regulations, tread depth—no less than 2/32” remaining, at all times, over 75% of the tire.

There are no specific sizes listed because of the large diversity of Group 8 cars. All Group 8 cars must use similar sized tires to what was used in the day, which is pre 1973. Using oversized tires is unacceptable and when in question, SVRA’s determination shall be the final word.

Wheels may be of an alternate material but must be of period design. They must be the correct diameter and width as specified within the Supplemental Regulations of the Make and Model.

Any Treaded, DOT approved Tires with a UTQG of 100 or greater with appropriate Speed Rating and a minimum Aspect Ratio of 45 Note: Group 8 must use approved full molded treaded tires, regardless of what specification tires a car may have competed with in a prior race series.

Tires may not extend beyond the fender opening at the highest point of the tire.

For Toyo RA1’s and Nitto NT01’s, please see page 6 of this document

Group 9

Approved tires:

Monoposto Racing Rules and Regulations: monoposto.com

Suitable and appropriate slicks and treaded tires.

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Group 10

Approved Tires:

Group 10 cars are expected to have only period-correct equipment and specifications.

Racing SLICKS. While exact size and aspect ratio are not specified, entrants must ensure that tire choice is appropriate for the car during the eligibility period.

Group 11

Approved Tires:

Group 11 cars are expected to have only period-correct equipment and specifications.

Racing SLICKS. While exact size and aspect ratio are not specified, entrants must ensure that tire choice is appropriate for the car during the eligibility period.

Group 12

GTU, MP1-3 Approved Tires:

Tire sizes must be used as listed in your cars specific racing series.

Wheels may be of an alternate material but must be of period design. They must be the correct diameter and width as specified within your cars specific racing series Tires may not extend beyond the fender opening at the highest point of the tire.

Note: Group 12 must use above listed approved tires, regardless of what specification tires may have used in a prior racing series. Specifically Prohibited: Slicks Tires

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Toyo RA-1 Wear Depths Full Tread Depth

5/32

3-4/32

2/32

These tires barely meet the spirit of the tire rules at 5/32nds and are more like Slick Tires than a Block or Vintage tread pattern. For 2017 - 4 grooves on these tires will be allowed and 2 grooves showing will be considered illegal, if a car has 2 grooves after a race the car will be disqualified. For 2018 these tires will be removed from the approved tire list.

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Nitto NT01 Wear Depths Full Tread Depth

3/32nds

Legal

Illegal

For 2017, 2 grooves will be considered illegal, if a car has 2 grooves after a race the car will be disqualified. For 2018 these tires will be removed from the approved tire list.